c/102763 - fix ICE with invalid input to GIMPLE FE

This fixes an ICE for the failure to verify we're dereferencing a
pointer before throwing that at build_simple_mem_ref.

2021-10-15  Richard Biener  <rguenther@suse.de>

	PR c/102763
gcc/c/
	* gimple-parser.c
	(c_parser_gimple_postfix_expression_after_primary): Check
	for a pointer do be dereferenced by ->.

gcc/testsuite/
	* gcc.dg/gimplefe-error-12.c: New testcase.

diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
index c43ee38a2cfd9f1a2d56e31ef0c0a97b06058c71..f3d99355a8eb78f6c59ed1cdd6b3b97dd306f7e5 100644 (file)
--- a/gcc/c/gimple-parser.c
+++ b/gcc/c/gimple-parser.c
@@ -1817,6 +1817,14 @@ c_parser_gimple_postfix_expression_after_primary (gimple_parser &parser,
        case CPP_DEREF:
          {
            /* Structure element reference.  */
+           if (!POINTER_TYPE_P (TREE_TYPE (expr.value)))
+             {
+               c_parser_error (parser, "dereference of non-pointer");
+               expr.set_error ();
+               expr.original_code = ERROR_MARK;
+               expr.original_type = NULL;
+               return expr;
+             }
            c_parser_consume_token (parser);
            if (c_parser_next_token_is (parser, CPP_NAME))
              {

diff --git a/gcc/testsuite/gcc.dg/gimplefe-error-12.c b/gcc/testsuite/gcc.dg/gimplefe-error-12.c
new file mode 100644 (file)
index 0000000..981ff7b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gimplefe-error-12.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-fgimple" } */
+
+int get_current ();
+
+__GIMPLE
+void foo()
+{
+  get_current()->flags; /* { dg-error "non-pointer" } */
+}